1. The Role of Biological Control
Become
Bug-Wiser
The Role of Biological Control
in Landscape IPM
Ray Ridlen
Extension Educator
Hort./Ag.

2. Integrated Pest Management
…is an environmentally friendly and less expensive way of managing the pests in the urban yard
…is made up of four key strategies

3. Cultural Control
This is all about prevention, and is a key feature of IPM. It includes:
Cleaning up debris where pests can hide
Cleaning up dead plants in the garden so pests cannot survive the winter there
Using plants that are resistant to pest damage or plants that can tolerate damage
Rotating the plants in the garden from year to year, so that disease doesn’t build up in that spot
Putting plants where they will be healthier or are less attractive to pests

4. Physical Control
Removing insects by hand, such as plucking bagworms off the shrubs
Cutting off infected portions of the plant, such as pruning tree branches that are covered with Fall Webworm caterpillars
Crushing insects, such as insect eggs
Trapping to remove insects

5. Chemical Control
This should be the last thing you think of, not the first, when you want to control pests in the yard
Use chemicals sparingly
Use chemicals only when needed
Use chemicals only where needed
Use chemicals that are easier on the environment, such as:
Bt (Bacillus thuringiensis)
Horticultural oils
Horticultural soaps
Insect growth regulators (IGR)

6. Biological Control
In undisturbed land, such as native prairie and forests, insects and plants live in harmony, with the numbers of insects that feed on plants kept in check by a variety of predators, diseases, and parasites. To some extent, this natural cycle can occur in homeowners’ yards.

8. Predators The helpers that you will see the most often in
the yard are the predators
They are usually larger than the insects they
eat
They eat a lot of insects
They are usually fast moving
They are generalists as a rule, so they’ll eat pests, non-pest insects, and even each other at times

9. Lady Beetles The adult beetles are usually orange or pink with or
without black spots, though they can also be solid
black
Lady beetles are voracious eaters, and eat lots of aphids
They will also eat insect eggs and young caterpillars

10. Lady beetle eggs
Lady beetle larvae
Lady beetle pupa
Lady beetle adults

11. This is the called the mealybug destroyer, but it is just another kind of lady beetle.
Lady beetles hibernate (diapause) as adult beetles over
the winter in sheltered places
Lady beetles, like all insects, are cold-blooded
The female lady beetle lays her eggs near aphids
A lady beetle will let out a foul-smelling yellowish liquid
when it is frightened. This will repel any would-be
predators
Lady beetles can fly about 15 miles per hour

12. Unfortunately, not every member of the Family
Unfortunately, not every member of the Family Coccinellidae is a beneficial. There are two species in this Ladybeetle family that are pests
Mexican bean beetle
Leaf damage on beans caused by the Mexican bean beetle
Squash beetle

13. Lacewings Their larvae are so predaceous, they are called aphidlions
Lacewing eggs
Lacewings
Lacewings are in the order Neuroptera, meaning “nerved wings”
Their larvae are so predaceous, they are called aphidlions
Lacewing adults
Lacewing larva
Lacewing pupa

14. The lacewing larva’s jaws are hollow. It pierces the
The lacewing larva’s jaws are hollow. It pierces the aphid, holds it up, and drains out the juices, leaving behind the empty skin
Lacewing larvae do not poop! Their diet is aphid-juice, so there’s little solid material. Instead, when they molt for the final time into a pupa, the larval skin contains all the frass.
Most lacewings are predators
The most common lacewing is green, but there is also another family that is brown:

15. Praying Mantis Praying mantids are generalist predators
There is no pupal stage
Mantids can look over their shoulder
Egg case
Nymph
Adult

16. Syrphid Fly Also called hover fly or flower fly
The syrphid larva (the proper term for a fly larva is maggot) feeds on aphids and other small, soft-bodied insects
Syrphid Fly

17. Spiders Spins a web……………Actively hunts…….……Lies in wait Brown recluse
(Fiddle-back)
Black widow

18. Ground Beetles Ground beetles are fast-moving generalist predators
They will eat anything they find on the ground, such as caterpillars or leaf-feeding beetles that get knocked off the plant
Even the larvae are predaceous

19. Wasps Wasps are efficient generalist predators
Paper wasps, mud daubers, hornets, yellowjackets, cicada killers all prey on insects

20. Other Predators Spiny soldier bug Minute pirate bug Daddy longlegs
Predaceous mite

21. Parasite vs. Parasitoid
Both are smaller than their host
Both have a part of their life stage that feeds an organism of a different species
Parasite vs. Parasitoid
A successful parasite does not kill its host. It needs its host to help it move around to infect others
A parasitoid is a parasite of a host, but when the parasitoid emerges, it kills its host

22. Parasitoids
There are more helpers that you are less likely to see because they are so tiny. These creatures include
some flies and tiny wasps.
They are much smaller than the insects they eat
They usually only consume one host
They are often very picky about what insects they eat, and usually are species-specific
These tiny wasps do not sting people
The female wasp or fly will lay her eggs inside or on top of a host insect, usually in the egg, larva, or pupa.
The young wasp/fly will burrow inside the “host” and
eat it from the inside out. When the wasp or fly is ready to pupate, the host will be killed.

23. There are many successful parasitic wasps
This wasp lays its eggs in aphids. The parasitized aphid becomes swollen, brown, and dry, and is referred to as a mummy

24. This is a parasitic wasp, looking over insect
eggs, deciding where to lay her own eggs
Courtesy of The Ohio State University
Wasp larvae have finished eating out this
caterpillar. They will now spin cocoons,
pupate, and emerge later as wasps,
ready to lay eggs in another insect victim
Courtesy of The Ohio State University
This tomato hornworm is carrying
around wasp pupae on its back.
The wasp larvae have eaten out most
of this caterpillar, so it will not
develop into a moth
Courtesy of The Ohio State University

25. Not all parasitoids are wasps
Not all parasitoids are wasps. Tachinid flies are also excellent biological control agents for a number of pest insects

26. Pathogens Finally, there are diseases that insects can get, referred
to as pathogens. Here are a few examples:
These caterpillars were killed by a virus
This aphid was killed by a fungus.
In fact, when it’s warm and humid
in the spring, many aphids (and
other insects) are killed by fungi

27. Nematodes Nematodes are tiny worms (roundworms)
Nematodes can be free-living, but many are parasitic
Some species of nematodes are important plant pests (e.g., pine wilt nematode, soybean cyst nematode)
Entomopathogenic nematodes are used as biological control agents of insect pests
Two key biocontrol nematodes are
Steinernema – The Ambushers
Heterorhabditis – The Hunters

28. Nematodes spilling out of a beet armyworm pupa
Nematodes are most effective against soil-dwelling insects
Nematodes must be applied in large numbers and kept moist
Nematodes are fairly species-specific
Nematodes in a fungus gnat larva
Nematodes in a maggot
Nematodes spilling out of a beet armyworm pupa

29. What you can do to help
Remember that the insect predators and parasites are
just as susceptible to insecticides as are the insect
pests. So only use a chemical insecticide when absolutely necessary, and apply it only where it is needed. Also, try to apply the chemical in the early morning or at dusk, when predators and parasites are not as active.
Rely on IPM techniques; most of these do not harm the
natural enemies of the insect pests
Encourage parasites by providing flowers that produce
nectar; while the larvae feed inside other insects, the
adults drink nectar from flowers
Predators and parasites can be purchased from biological control companies and released in your yard